Mac mini M5 Pro: 48GB vs 64GB for local AI
The Mac mini M5 Pro, 64GB holds 38 of the 55 current models here, and the Mac mini M5 Pro, 48GB holds 37. The Mac mini M5 Pro, 48GB costs $400 less. On Qwen3.8 27B, the strongest model both hold, they run at much the same speed: 12 and 12 tok/s, both estimated from memory bandwidth. The Mac mini M5 Pro, 48GB pays for itself sooner, in 155 years against 182 years at 500k tokens a day.
| Mac mini M5 Pro, 48GB | Mac mini M5 Pro, 64GB | |
|---|---|---|
| Price | $2,299 | $2,699 |
| Memory | 48 GB | 64 GB |
| Usable by the GPU | 36 GB | 48 GB |
| Memory bandwidth | 307 GB/s | 307 GB/s |
| Power under load | 140 Wstand-in | 140 Wstand-in |
| Models that fit | 37 | 38 |
| Best model it runs | Qwen3.8 27B | Qwen3.8 27B |
| Speed on that model | 12 tok/s estimated | 12 tok/s estimated |
| Pay-back on that model | Pays back in 155 years | Pays back in 182 years |
Neither power figure above is measured on the machine beside it. Both are stand-ins borrowed from the nearest hardware the data does have, so what the row shows is one borrowed figure printed twice. Each machine's page names the figure it borrows and why. Every pay-back figure on this page prices its electricity from these numbers.
Run the numbers on the Mac mini M5 Pro, 48GB · or the Mac mini M5 Pro, 64GB
How much use it takes to pay back
Everything above is at 500k tokens a day. Pay-back moves with how much you actually run, so here are both machines on Qwen3.8 27B, the strongest model both hold, at the five levels of use the calculator names. The Mac mini M5 Pro, 48GB pays back sooner at every level of use, so this is not a choice that turns on how hard you work it.
| A day's use | Mac mini M5 Pro, 48GB | Mac mini M5 Pro, 64GB |
|---|---|---|
| 50ka few chats a day | 1,549 years | 1,818 years |
| 200klight assistant use | 387 years | 454 years |
| 1Ma moderate coding-assistant day | 77 years | 91 years |
| 4Mheavy coding with an agent | 19 years | 23 years |
| 20Magents running most of the day | 4.5 yearsits ceiling | 5.3 yearsits ceiling |
On Qwen3.8 27B neither machine can generate 20M tokens a day: the Mac mini M5 Pro, 48GB manages at most 17.1M and the Mac mini M5 Pro, 64GB at most 17.1M. Both figures on that row are for the most each can do.
Run the Mac mini M5 Pro, 48GB at 20M tokens a day · or the Mac mini M5 Pro, 64GB
What the extra memory buys
The Mac mini M5 Pro, 64GB holds 1 model the Mac mini M5 Pro, 48GB cannot at 32k of context. That is what the difference in memory actually buys.
| Model | Weights | Needs at 32k | On the Mac mini M5 Pro, 64GB |
|---|---|---|---|
| Ripple 65B Previewnot yet placed | 39 GB | 41 GB | 5.6 tok/s estimated |
The extra memory buys context as well. Of the 37 current models both machines hold at 32k, 4 run to a longer window on the Mac mini M5 Pro, 64GB: the weights are a fixed size and the KV cache is not, so what the weights leave spare is what a longer context grows into. Gemma 4 31B it reaches 256k there against 128k on the Mac mini M5 Pro, 48GB, each the longest window the calculator offers that the machine still holds it at.
The Mac mini M5 Pro, 48GB is also head to head with another computer: GMKtec EVO-X2, 64GB · MacBook Pro M5 (14-inch), 32GB. With the same machine at another memory size: 24GB. With the machine it replaced: Mac mini M4 Pro, 48GB.
The Mac mini M5 Pro, 64GB is also head to head with another computer: Mac Studio M5 Max, 36GB. With the same machine at another memory size: 24GB. With the machine it replaced: Mac mini M4 Pro, 64GB.
Both sizes have a page of their own, with every machine here sold at that size, the models that fit it and what one step of memory buys: what 48 GB runs · what 64 GB runs.
The assumptions behind both columns
Both columns use the same usage: 500k tokens a day at 15:1 input to output, 32k of context, $0.17 per kWh, and today's API prices held flat. Speeds marked estimated are worked out from memory bandwidth rather than measured, and pay-back scales with them. Change any of it in the calculator.
More head to head: everything the Mac mini M5 Pro, 48GB runs · everything the Mac mini M5 Pro, 64GB runs · every other match-up · the quickest pay-back at each level of use · every model against the frontier